Amniocentesis for lung maturity how long for results

Your health care provider or a genetic counselor will help you understand your amniocentesis results. For genetic amniocentesis, test results can reliably rule out or diagnose various genetic conditions, such as Down syndrome.

However, amniocentesis can't identify all genetic conditions and birth defects. If amniocentesis indicates that your baby has a chromosomal or genetic condition that can't be treated, you might face wrenching decisions — such as whether to continue the pregnancy. Seek support from your health care team and your loved ones.

For fetal lung maturity amniocentesis, test results can reliably indicate a baby's lung maturity. If you need to deliver the baby early, this information can offer reassurance that your baby is ready for birth. Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission. This content does not have an English version. This content does not have an Arabic version. Sections for Amniocentesis About. Overview Amniocentesis Open pop-up dialog box Close.

Amniocentesis Amniocentesis is a prenatal test. Request an Appointment at Mayo Clinic. Share on: Facebook Twitter. Show references Ghidini A, et al. This may be slightly painful. You may feel some cramping as the needle enters the uterus. The doctor will withdraw a small amount of amniotic fluid into a syringe.

The amount depends on the type of testing that will be done, but usually no more than an ounce is removed. Your body will make fluid to replace the amount taken out. You may feel a tugging or pulling feeling as the fluid is removed.

If you are Rh negative, you may be given Rhogam, a special injection that can prevent an Rh negative mother's antibodies from attacking Rh positive fetal blood cells. You and your fetus will be monitored for a time after the procedure. Your vital signs and the fetal heart rate will be checked regularly for an hour or longer. The amniotic fluid sample will be sent to a genetics lab. Alpha-fetoprotein, a protein made by the fetus and present in the fluid, may be measured to rule out an open neural tube defect, such as spina bifida.

Testing may also be done for other substances related to metabolic or genetic conditions. Depending on test results, counseling with a genetics specialist may be advised. Search Encyclopedia. Why do I need this test? You may be at risk for early delivery if you have any of these conditions: Gestational diabetes High blood pressure in pregnancy Your water breaks early premature rupture of amniotic membranes The placenta can't fully support the baby growing in the uterus placental insufficiency Rh disease erythroblastosis What other tests might I have along with this test?

What do my test results mean? The range of results are: A ratio of less than 1. How is this test done? Amniotic fluid can be collected in 2 ways: Amniocentesis. Does this test pose any risks? If amniocentesis is done, the risks can include: Leaking of amniotic fluid. Injury to the baby. This can happen if the needle touches the baby. What might affect my test results?

Many factors can affect your test results. These include: Fetal or maternal blood in the amniotic fluid Abnormally high volumes of amniotic fluid, which may give false-low test values Fetal meconium stool.

This is when the baby has a bowel movement in the uterus. How do I get ready for this test? The cells in the fluid sample are grown in a special culture and then analyzed the specific tests done on the fluid depend on personal and family medical history.

Amniocentesis is usually done between 15 and 20 weeks, but can be done later in pregnancy if needed. Timing varies depending on what is being tested for, but results usually are available within 1 to 2 weeks.

Tests of lung maturity are often available within a few hours. Reviewed by: Armando Fuentes, MD. Larger text size Large text size Regular text size.